1. Technical Field
The invention disclosed herein relates generally to belt tensioners for seatbelt systems. More particularly, the present invention relates to a serviceable seatbelt buckle and tensioner assembly that is readily removed and re-installed.
2. Description of the Prior Art
In the area of occupant protection in a vehicle, the ever-increasing use of seatbelt tensioners has achieved a level where almost every new vehicle now includes one of these devices as part of its safety system.
One popular variation of the seatbelt tensioner is the seatbelt buckle and belt tensioner assembly, which is well-known. The seatbelt buckle and belt tensioner assembly may also be referred to herein using such terms as buckle tensioner, buckle tensioner assembly, buckle mounted tensioner or buckle mounted belt tensioner. The buckle portion of a buckle tensioner is releasably attachable to a tongue that is slidably affixed to a vehicle's seatbelt assembly by buckling once the occupant is in the seat. In the event, or anticipation, of sudden deceleration of the vehicle, an on-board sensor senses the abrupt change in vehicle motion and generally causes an electrical signal to be sent to an energy generating device such as a deployable pyrotechnic, stored gas or electric device or component. For example, one well known from of energy generating pyrotechnic device includes a cartridge, typically fluidly connected to a generally enclosed cylindrical container having a piston or similar feature movably fitted therein. The piston is commonly attached to the seatbelt buckle by a cable or similar flexible load carrying member. When the energy generating device is activated by the signal received from the sensor, an expanding gas is delivered from the cartridge to the interior of the cylinder by way of the fluid connection, the resultant gas pressure effecting movement of the piston and pulling on the seatbelt buckle by way of the interfacing cable connection. The seatbelt is thus tensioned and is tightened against a belted occupant in the seat.
The advent of forward-looking sensing for vehicles (pre-impact, predictive sensing or threat detection), vehicular stability control, lane departure, rollover, pedestrian, foreign object, occupant awareness detection and/or similar predictive impact or loss of vehicle control sensing, has opened the prospect of deploying restraint countermeasures prior to the occurrence of an actual impact or loss of vehicular control, etc. As many of these technologies contain predictive logic, it is conceivable that a buckle mounted belt tensioning device may be pre-activated in anticipation of a collision that may ultimately be avoided by the driver, thus increasing the frequency of need for removal, replacement or re-installation of a seatbelt buckle tensioner. In addition, like other deployable pyrotechnic or stored gas types of devices used in vehicle safety systems, such as air bags, many seatbelt buckle-mounted belt tensioners are currently capable of single-event usage. These devices are generally intended to deploy in moderate to severe impact events. After a single deployment, such buckle mounted belt tensioners must be replaced. Belt tensioner assembly access may also be required to otherwise service, calibrate, or reset a vehicles reusable or resettable buckle mounted belt tensioning device.
In consideration of an increased need for servicing and replacing buckle mounted belt tensioners, ease of serviceability becomes a relevant factor in the design of these devices. In the case of known buckle mounted belt tensioners, the attachment features in many cases are inaccessible and the devices cannot be easily removed, reinstalled or replaced without necessitating the detachment and removal of either or both of the complete vehicle seat, and/or center console assembly based on tool clearance and package space limitations. Removal of either or both of these assemblies is labor intensive and costly. In addition to increased inconvenience and expense, removal of either the vehicle seat or the console to facilitate belt tensioner replacement increases the risk of functional or cosmetic handling damage to these or nearby interior components, introduction of squeak and rattle issues, disconnected or damaged wiring or electrical connections, etc., given the substantial content incorporated in the modern vehicle seat, such as heating and cooling elements, electric motors, bladders, pumps, seat track mechanisms, electric and manual lever controls, occupant classification systems and associated electrical wiring and connections.
Accordingly, there is a need in the art of seatbelt buckle mounted belt tensioners for a system that may be readily serviced without the need of removing adjacent components such as the vehicle seat or the console.